This invention relates to the art of broadcast couplers for radios and communications equipment located in vehicles, and more particularly to a new and improved broadcast coupler for coupling an unmodified vehicle antenna to communications equipment and a broadcast radio receiver in the vehicle.
An important area of use of the present invention is antenna systems for vehicles for operation with both standard broadcast radio receivers and additional communications equipment such as receivers, transmitters or transceivers for surveillance, law enforcement and similar functions. There are broadcast couplers which are commercially available which will couple such additional communications equipment into an original equipment manufacture (OEM) antenna without tuning. Lack of tuning capability can be a disadvantage, however, because the vehicle manufacturer does not control the antenna characteristics closely in the broadcast frequency range, much less any other frequency ranges of interest. Other commercially available devices will tune a modified replacement antenna for coupling to such communications equipment. This, however, has the disadvantage of added expense in replacing the OEM supplied antenna.